Goldman Sachs upgraded UnitedHealth Group (NYSE: UNH) from Neutral to Conviction Buy with a price target of $66.00 (from $57.00).

The firm cited a favorable view of the 2013 operating outlook along with higher confidence that UNH will grow earnings in 2014. "We expect increased investor visibility on these factors will drive multiple expansion over the next 6-12 months," the analyst said.

While 2013 is important, Goldman believes investor sentiment toward the health reform implementation in 2014 and beyond will continue to be the driving factor for managed care stocks.

"For UNH, we see health reform implementation downside risk somewhat more "contained" than we had previously, which is a key factor in our view of the attractive risk-reward profile at current valuation levels," the analyst said.

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